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    <script>
        //1、==比较时会转换类型，（只比值，不不比类型）
        //2、===比较时不会类型转换、（不仅要比值还要比类型）

        console.log(1=="1");  //true
        console.log(1==="1");  //false

        console.log(undefined==null);  //true
        console.log(undefined===null);  //false

        console.log(5==new Number(5));  //true
        console.log(5===new Number(5));  //false
        
    </script>
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